An air conditioner (AC) is an electromechanical system, which means it has both electrical and mechanical parts. Malfunctions can occur on both sides of the system, leading to inefficient cooling. Here are some of the electrical malfunctions that can attack your AC:
The capacitor's role is to store static electricity which is then used to boost and stabilize the incoming voltage so that it can start the AC motor. This is necessary because the motor needs a high and precise voltage level for it to work efficiently. The blower motor, outdoor fan motor, and the compressor motor each has its own capacitors (run and start capacitors).
The capacitor loses its capacitance (charge carrying capacity) each time it is used, which means it will weaken over time. When a capacitor weakens to the point where it cannot deliver the required voltage, your AC will have a hard time starting and running, making it inefficient.
A short circuit occurs when electrical power diverts from its intended channel and flows through an unintended path. A good example is if an electrical wire loses its insulation and comes into contact with another wire or conductor. There are several causes of electrical short-circuit, anything that causes electricity to divert from its intended path can cause it.
For example, a serious storm can damage the AC, loosen a few wires and cause a short circuit. Another example is when lighting or a power surge overwhelms your AC with electricity, causing damaging insulation and forcing electricity to flow where it shouldn't flow. A short circuit can damage other parts of the AC (for example, it can fry the motors) or even cause an electrical fire. This is why, if your AC has been damaged in a storm, you need to call for emergency repairs before running it again.
The thermostat is also another electrical part of the AC that can malfunction and prevent the AC from functioning efficiently. There are two main causes of thermostat malfunctions: battery issues and wire attachment issues. Sometimes you may think that your thermostat is damaged while, in the real sense, its batteries are dead. The thermostat may also start acting up if the wires attaching it to the rest of the AC system are loose.
Don't try to handle AC electrical problems on your own; you risk getting a nasty shock or even causing further damage. Instead, leave such problems in the hands of professional technicians or HVAC specialists.